Apparatus for suspending sheet glass



July 8, 1969 L. L. BOGNAR APPARATUS FOR SUSPENDING SHEET GLASS Sheet orz' Filed 001.. 5, 1967 INVENTOR LEWIS L. BOGNAR BY ATTORNEY I July 8; 1969 L. L. BOGNAR AI PARATUS FOR SUSPENDING SHEET GLASS Sheet Filed on. 5 1967 INVENTOR LEWIS L. BOGNAR ATTORNE Y 3 454 298 APPARATUS FOR SIlSPllNDING SHEET GLASS Lewis L. Bognar, Painted Post, N.Y., assignor to Corning Glass Works, Corning, N.Y., a corporation of New York Filed Oct. 5, 1967, Ser. No. 673,124 Int. Cl. B66c I/42, 1/44 U.S. Cl. 294--118 5 Claims ABSTRACT OF THE DISCLOSURE Background of the invention in forming articles from sheet glass it has been customary to support the sheet in a vertical plane so as to minimize distortion and elongation of the sheet as it is brought up to elevated temperatures for forming. However, the support means utilized in the prior art consisted of rather rigidly suspended gripping tongs which were secured to a roller or slide block for transporting the sheet but which did not allow any movement within the plane of the sheet. In some instances a movable carriage was utilized in conjunction with the suspended tongs to add further support to the bottom edge of the sheet. Although the movable carriage prevented viscous elongation of the sheet, it was not entirely satisfactory since it induced transverse distortion and warpage. Further, the rigid top suspension of the sheet had a tendency to induce buckling within its longitudinal plane during heatup, and prevented uniform movement thereof during forming.

Summary of the invention The present invention is directed to a specific apparatus for facilitating both vertical and longitudinal movement within the plane of a vertically suspended sheet of glass. When forming articles from sheet glass, I have found that improved quality can be obtained by permitting the glass to uniformly how in both the vertical and longitudinal plane of the glass radially into the forming members. However, when the glass is rigidly suspended from above, it is virtually impossible to allow any vertical movement of the sheet from above downwardly into the forming members, thus resulting in siding and distortion. Further, as the sheet is heated to its forming temperature prior to the forming operation, there is a tendency for the sheet to expand in the longitudinal direction, and accordingly the sheet has a tendency to buckle when it is rigidly supported.

The instant apparatus alleviates these problems by pivotally suspending gripping tongs from a sliding or rolling support through a downwardly movable friction lock mechanism. The support, which may be in the form of a bearing block, is slidable along an overhead rail for transporting the sheet, and slidably retains a pair of rods for a limited vertical movement. The lower ends of the rods are connected together and the gripping tongs are pivotally suspended therefrom by means of a universal type joint, so as to facilitate the pivotal movement of the tongs about both a horizontal axis normal to the plane of the sheet and a horizontal axis within the plane of the sheet. One of the vertically movable rods has a plurality of teeth or grooves formed in an outer surface thereof which frictionally engage a ball or detent United States Patent 0 "ice of a variably adjustable friction lock mechanism, so as to permit a limited downward movement of the tongs and accordingly the sheet retained thereby upon the application of a predetermined force thereto.

It thus has been an object of the present invention to provide improved apparatus for suspending sheet glass in a vertical plane while permitting both longitudinal and vertical movement within the plane of such sheet to compensate for both thermal and mechanical forces exerted thereon.

Description of the drawings FIG. 1 is a perspective view of apparatus embodying the invention.

FIG. 2 is a front elevational view, partially in section, of the apparatus shown in FIG. 1.

FIG. 3 is a side elevational view of the apparatus shown in F'IG. 2.

Description of the preferred embodiment An overhead support rail or shaft 12 is shown fixedly positioned by means of flange supports 14. A bearing block 16 is slidably positioned on support shaft 12, and has a tapered upper opening 18 which facilitates the sliding movement of the block along shaft 12 past support flanges 14.

A pair of guide blocks 20 are positioned in vertical alignment on one side of the bearing block 16, and sildably receive a slide rod 22 having an upper terminal stop 24. The opposite side of the bearing block 16 has a guide block 26 which slidably receives a control rod 28 provided with an upper terminal stop 30. The control rod 28 has a plurality of teeth or grooves 32 formed in the outer face thereof which are cooperatively engaged by a ball or detent 34 of a frictional adjusted member 36. The adjustment member 36 is secured to the bearing block 16 by means of a bracket 38, and has an adjust- A hanger rod 50 is suspended from tie rod 44 and has a hanger member or tongs 52 pivotally secured to the lower end thereof by means of U-shaped collar 54 providing a universal type joint. A pivot pin 56 connects the collar 54 to hanger rod 50* so as to permit pivotal movement of the tongs 52 longitudinally along the plane of the sheet glass G, about an axis which is normal to the plane of the vertically suspended sheet. The shoulder links 58 of the tongs 52 are pivotally connected at their outer ends by pins 60 to arm members 62, and at their inner ends to collar 54 by pin means 64. Pin means 64 permits pivotal movement of the tongs 52 transversely of the plane of the sheet glass G, about a horizontal axis lying within the vertical plane of such sheet. The arm members 62 are pivotally connected together at 66 in the customary manner, so that the weight of the glass sheet G creates a gravity locking action between adjustable holding pins 68.

In operation, the bearing block 16 is slid along overhead support shaft 12 to a loading position, wherein cam followers 46 engage short cam tracks 48 to position shown in FIG. 3 the friction locking mechanism, including rods 22, 28, 44 and 50, in an up or loading position. That is, when a sheet is being formed, the pressure exerted thereon by the forming members will normally cause the sheet to move downwardly upon reaching a predetermined force, and accordingly it is necessary to reposition the tongs in their upper loading positionprior to suspending a new sheet to be formed. The downward movement of the sheet is accomplished through the controlled fricitonal engagement between detent 34 and teeth 32 of control rod 28, as set by adjusting screw 40, so that rods 22, 28, 44 and 50 may move downwardly upon application of a desired force thus lowering the tongs 52 and its suspended sheet G.

The adjustable holding pins 68 grip the glass sheet G close to its upper edge, and although only one set of tongs is shown, the sheet is supported in a vertical position by a plurality of such gravity locking tongs. Initially, the tongs are applied to the sheet so that they are pivoted about pivot pin 56 toward the longitudinal center of the sheet as shown in FIG. 3. With both ends of the sheet supported with the tongs pivoted toward the longitudinal center thereof, the inherent longitudinal expansion of the sheet which accompanies the required heatup prior to forming, is taken into consideration. That is, as the sheet expands longitudinally during the heatup, the tongs 52 may pivot about the axis of pin 56 longitudinally of the sheet and back downwardly toward the vertical position, so as to compensate for such expansion without inducing buckling of the sheet.

The sheet is indexed from the heatup station of a forming station by sliding bearing block 16 along shaft 12. The forming members exert a predetermined pressure on the sheet tending to draw the glass radially inwardly of the forming cavity from all directions. Accordingly, if the tongs were not fee to move downwardly with the pulling force on the glass, the glass would have a tendency to attenuate, thus producing an unacceptible article having uneven wall thickness. However, the pull exerted on the glass by the forming members is transferred through the tongs 52, collar 54, hanger rod 50 and tie rod 44 to rods 22 and 28. The weight of the glass alone is not sufficient to cause the tongs to move downwardly. However, frictional adjustment member 36 is pre-set, by means of adjustment screw 40, so that compression spring 42 urges ball 34 against teeth 32 of control rod 28 with a desired force such that the whole mechanism is allowed to move downwardly when a predetermined force is exerted on sheet G. That is, the sheet is pulled downwardly through the action of the forming members, the pulling force exerted on the tongs is transmitted to control rod 28 so that the teeth 32 depress the ball 34 upon the application of a predetermined force, to allow the necessary downward vertical movement of the sheet.

Since the glass is drawn into the forming cavity from all sides within the plane of the sheet, it can be seen that pivot pin 56, permitting the tongs to move along the longitudinal plane of the sheet about an axis normal thereto, facilities a uniform flow of the sheet within the forming cavity from all directions. Pivot pin 64 allows freedom of movement of the sheet transversely to the plane thereof so as to facilitate reception of the horizontally operable forming members engaging opposite sides of the sheet. After an article has been formed and the sheet removed from the holding pins 68 of tongs 52, bearing block 16 is slid along overhead shaft 12 back to the loading station where the friciton locking 4 mechanism is again cammed to the upper loading position for a repeat cycle.

Although I have disclosed the now preferred embodiment of the inveniton, it will be apparent to those skilled in the art that various changes in modification may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

-I claim:

.1. Improved apparatus for suspending sheet glass from means horizontally movable along an overhead track for facilitating the forming of articles from such sheet wherein the improvement comprises, means for gripping said sheet, means connected to said horizontally movable means for facilitating vertical movement of said gripping means and the sheet of glass suspended therefrom upon the application of a predetermined force to said sheet, and pivot means connecting said gripping means to said vertical movement facilitating means for facilitating pivotal movement of said gripping means longitudinally of said sheet about an axis substantially normal to the vertical plane thereof.

2. Apparatus for suspending sheet glass as defined in claim 1 wherein said means for facilitating vertical movement includes a pair of vertically extending members slidably connected to said horizontally movable means, means for connecting said vertically extending members together at one end for supporting said gripping means, a plurality of grooves formed .in one of said vertically extending members, and means for applying a variable fricitonal pressure to said grooves to retain said vertical members in position and permit vertical movement thereof upon the application of a predetermined force.

3. Apparatus for suspending sheet glass as defined in claim 2 wherein said means for applying a variable frictional pressure include an adjustment screw operable upon a compression spring which urges a detent into engagement with said grooves, wherein a predetermined force applied to said vertical members will compress said detent against said spring and permit the grooved member to move downwardly.

4. Apparatus for suspending sheet glass as defined in claim 1 wherein said gripping means includes gravitylocking tongs, and said tongs are connected to said means for facilitating vertical movement through a U-shaped collar providing a universal type joint so that said tongs may pivot about an axis within the plane of the suspended sheet and an axis normal to such plane.

5. Apparatus for suspending sheet glass as defined in claim 1 wherein means reposition said vertical movement means in an upward loading position.

References Cited UNITED, STATES PATENTS 2,115,106 4/1938 Hinsey 294-118 2,710,493 6/1955 Glynn 294-119 3,010,753 11/1961 Russ et al. 294-118 3,084,969 4/1963 Davidson et a1 294-118 ANDR'ES H. NIELSEN, Primary Examiner.

US. Cl. X.R. -106, 273 

